title: Practical precooling: effect on cycling time trial performance in warm conditions.
abstract: The purpose of this study was to compare the effects of two practical precooling techniques (skin cooling vs. skin + core cooling) on cycling time trial performance in warm conditions. Six trained cyclists completed one maximal graded exercise test (VO2(peak) 71.4 +/- 3.2 ml x kg(-1) x min(-1)) and four approximately 40 min laboratory cycling time trials in a heat chamber (34.3 degrees C +/- 1.1 degrees C; 41.2% +/- 3.0% rh) using a fixed-power/variable-power format. Cyclists prepared for the time trial using three techniques administered in a randomised order prior to the warm-up: (1) no cooling (control), (2) cooling jacket for 40 min (jacket) or (3) 30-min water immersion followed by a cooling jacket application for 40 min (combined). Rectal temperature prior to the time trial was 37.8 degrees C +/- 0.1 degrees C in control, similar in jacket (37.8 degrees C +/- 0.3 degrees C) and lower in combined (37.1 degrees C +/- 0.2 degrees C, P < 0.01). Compared with the control trial, time trial performance was not different for jacket precooling (-16 +/- 36 s, -0.7%; P = 0.35) but was faster for combined precooling (-42 +/- 25 s, - .8%; P = 0.009). In conclusion, a practical combined precooling strategy that involves immersion in cool water followed by the use of a cooling jacket can produce decrease in rectal temperature that persist throughout a warm-up and improve laboratory cycling time trial performance in warm conditions.
authors.affiliation: Department of Physiology, Australian Institute of Sport, Canberra, ACT, Australia.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Quod
authors.forename: David T
authors.initials: DT
authors.lastname: Martin
authors.forename: Paul B
authors.initials: PB
authors.lastname: Laursen
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Gardner
authors.forename: Shona L
authors.initials: SL
authors.lastname: Halson
authors.forename: Frank E
authors.initials: FE
authors.lastname: Marino
authors.forename: Margaret P
authors.initials: MP
authors.lastname: Tate
authors.forename: David E
authors.initials: DE
authors.lastname: Mainwaring
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gore
authors.forename: Allan G
authors.initials: AG
authors.lastname: Hahn
mesh_terms: D000328:Adult; D001831:Body Temperature / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology; D003080:Cold Temperature; D018592:Cross-Over Studies; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D007101:Immersion; D008297:Male; D010807:Physical Endurance / Q000502:physiology; D013647:Task Performance and Analysis